Greetings Sailors. My name is Dan. I live in Albuquerque and am new to sailing. My 1983 MacGregor 21 has a bent mast. I have a new mast. In swapping out the hardware from one to the other, I seek advice and have a few questions. Are there any upgrades to components or design that I can incorporate into this refit? If this project has been detailed in video and available online, please share the link. If this project is detailed in writing please direct me to it. Overall, what components or fittings should be replaced, what components or fittings can be upgraded to a newer design and what components or fittings can be reinstalled?
Specifically:
Is it advised to change out all through-mast bolts (and nuts)? The hardware to which are attached shrouds, forestay and back stay look fine and will be reused. What about the through bolts?
It seems like a good time to change out the cheek pulley near the top on the starboard side. Mine is screwed in, but a drawing I have dated 3/7/77 indicates pop rivets (this must have been specific to the Venture). Are screws or rivets recommended?
The spreaders seem to have been set at three different heights (see photo). Why might this be? The three holes for the through bolts as measured from the foot are 9’6”, 10’1” and the spreader is currently at 10’6”. At what height should the spreaders be installed on the new mast? The drawing from 1977 indicates 10’6”.
Regarding the fitting that connects the spreader’s root to the mast: should these fittings be reused, or replaced or is there a newer design? Should the spreaders be replaced, or reused? Please see photos. And a related question: this fitting is fastened to the mast in three places; with a through-bolt, a screw, and a third bolt and nut. This third bolt is a bit of a mystery: the bolt heads seem to be on the interior of the mast. Please advise.
There are four cleats and other hardware fixed to the mast with screws. Exactly what screws are recommended? Stainless? Probably about 1/8” diameter and length of 1/2” to 3/4”, but what thread pattern (fine, coarse or medium)? Perhaps rivets would be better. Please advise.
Is there a newer design for the mast step and mast heel, or should I reinstall the existing mast heel (on the new mast)? The mast step has some gouges possibly from a grinder (see photo). Should it be replaced?
There is a masthead light and a deck light mounted high on the mast. I was led to believe that these were replaced in the last five to ten years and I plan to reuse them.
New Mast Mac 21
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DanCampbell
- Posts: 6
- Joined: Mon Jun 17, 2024 12:46 pm
- Sailboat: MacGregor 21
- Location: Albuquerque, NM
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OverEasy
- Admiral
- Posts: 2873
- Joined: Mon Sep 28, 2020 11:16 am
- Sailboat: MacGregor 26X
- Location: NH & SC
Re: New Mast Mac 21
Hi DanCampbell!
Welcome!
There really aren’t definitive answers to your questions but from a personal opinion perspective I can make some non-binding suggestions:
I’d suspect that the placement of the spreaders would be at the 10’6” location and would probably match your existing shroud cables.
The spreaders mainly have compressive forces applied into the mast, so you should be able to either use HD (preferably SST) pop rivets or you can possibly drill and tap in SST screws with locking compound and lock washers.
Light brackets and such can be HD (preferably SST) pop rivets or drill and tap in SST screws with locking compound and lock washers.
Pulleys have a bit of work going on so a SST bolt and Self Locking nut would be appropriate.
There isn’t any real harm in reuse of old hardware in good condition. That’s your judgement call.
It the spreader tubes are in good condition the same as above applies.
Personally if there is little chance I’d be removing something I’d use HD SST pop rivets over screws.
If using screws I’d use SST, drill and tap the holes, standard machine thread, use Locktite and lock washers. I’d be careful tightening so as not to strip the threads.
Hope this helps some.
It’s your boat, so your rules.
Best Regards,
Over Easy
Welcome!
There really aren’t definitive answers to your questions but from a personal opinion perspective I can make some non-binding suggestions:
I’d suspect that the placement of the spreaders would be at the 10’6” location and would probably match your existing shroud cables.
The spreaders mainly have compressive forces applied into the mast, so you should be able to either use HD (preferably SST) pop rivets or you can possibly drill and tap in SST screws with locking compound and lock washers.
Light brackets and such can be HD (preferably SST) pop rivets or drill and tap in SST screws with locking compound and lock washers.
Pulleys have a bit of work going on so a SST bolt and Self Locking nut would be appropriate.
There isn’t any real harm in reuse of old hardware in good condition. That’s your judgement call.
It the spreader tubes are in good condition the same as above applies.
Personally if there is little chance I’d be removing something I’d use HD SST pop rivets over screws.
If using screws I’d use SST, drill and tap the holes, standard machine thread, use Locktite and lock washers. I’d be careful tightening so as not to strip the threads.
Hope this helps some.
It’s your boat, so your rules.
Best Regards,
Over Easy
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DanCampbell
- Posts: 6
- Joined: Mon Jun 17, 2024 12:46 pm
- Sailboat: MacGregor 21
- Location: Albuquerque, NM
Re: New Mast Mac 21
Greetings OverEasy!
I really appreciate your suggestions.
This job awaits my full attention in a cooler month.
One concern I have is the holes that go straight through the mast, one at the spreaders and one up topped that receive a through bolt and nut. My guess is that the factory had a jig-set to assure the drill lined up perpendicular to the boat. I'll do my best but would be grateful for any pointers.
Thanks Again
Dan Campbell
I really appreciate your suggestions.
This job awaits my full attention in a cooler month.
One concern I have is the holes that go straight through the mast, one at the spreaders and one up topped that receive a through bolt and nut. My guess is that the factory had a jig-set to assure the drill lined up perpendicular to the boat. I'll do my best but would be grateful for any pointers.
Thanks Again
Dan Campbell
-
OverEasy
- Admiral
- Posts: 2873
- Joined: Mon Sep 28, 2020 11:16 am
- Sailboat: MacGregor 26X
- Location: NH & SC
Re: New Mast Mac 21
Hi DanCampbell!
Personally I’d make the time and effort to fabricate a drilling jig to get things lined up before drilling any holes. But that’s just me.
As with anything the preparations to do a thing properly is the difference between success and &$#@%!
You want the spreader brackets where they are supposed to be, aligned and uniform from side to side and at the proper angles.
The last holes I’d drill would be at the base foot as this can help you get everything you’ve done before that aligned with the boat centerline.
A slight rotational shift in mast extrusion profile left or right is gonna be better and less noticeable than having wonky angles of the spreader bars.
Best Regards,
Over Easy
Personally I’d make the time and effort to fabricate a drilling jig to get things lined up before drilling any holes. But that’s just me.
As with anything the preparations to do a thing properly is the difference between success and &$#@%!
You want the spreader brackets where they are supposed to be, aligned and uniform from side to side and at the proper angles.
The last holes I’d drill would be at the base foot as this can help you get everything you’ve done before that aligned with the boat centerline.
A slight rotational shift in mast extrusion profile left or right is gonna be better and less noticeable than having wonky angles of the spreader bars.
Best Regards,
Over Easy